1 files changed, 0 insertions, 90 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecT283R1Curve.cs b/crypto/src/math/ec/custom/sec/SecT283R1Curve.cs
index d8c462eeb..e659675ce 100644
--- a/crypto/src/math/ec/custom/sec/SecT283R1Curve.cs
+++ b/crypto/src/math/ec/custom/sec/SecT283R1Curve.cs
@@ -70,96 +70,6 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
get { return false; }
}
- /**
- * Decompresses a compressed point P = (xp, yp) (X9.62 s 4.2.2).
- *
- * @param yTilde
- * ~yp, an indication bit for the decompression of yp.
- * @param X1
- * The field element xp.
- * @return the decompressed point.
- */
- protected override ECPoint DecompressPoint(int yTilde, BigInteger X1)
- {
- ECFieldElement x = FromBigInteger(X1), y = null;
- if (x.IsZero)
- {
- y = B.Sqrt();
- }
- else
- {
- ECFieldElement beta = x.Square().Invert().Multiply(B).Add(A).Add(x);
- ECFieldElement z = SolveQuadraticEquation(beta);
- if (z != null)
- {
- if (z.TestBitZero() != (yTilde == 1))
- {
- z = z.AddOne();
- }
-
- switch (this.CoordinateSystem)
- {
- case COORD_LAMBDA_AFFINE:
- case COORD_LAMBDA_PROJECTIVE:
- {
- y = z.Add(x);
- break;
- }
- default:
- {
- y = z.Multiply(x);
- break;
- }
- }
- }
- }
-
- if (y == null)
- throw new ArgumentException("Invalid point compression");
-
- return this.CreateRawPoint(x, y, true);
- }
-
- /**
- * Solves a quadratic equation <code>z<sup>2</sup> + z = beta</code>(X9.62
- * D.1.6) The other solution is <code>z + 1</code>.
- *
- * @param beta
- * The value to solve the quadratic equation for.
- * @return the solution for <code>z<sup>2</sup> + z = beta</code> or
- * <code>null</code> if no solution exists.
- */
- private ECFieldElement SolveQuadraticEquation(ECFieldElement beta)
- {
- if (beta.IsZero)
- return beta;
-
- ECFieldElement zeroElement = FromBigInteger(BigInteger.Zero);
-
- ECFieldElement z = null;
- ECFieldElement gamma = null;
-
- Random rand = new Random();
- do
- {
- ECFieldElement t = FromBigInteger(new BigInteger(283, rand));
- z = zeroElement;
- ECFieldElement w = beta;
- for (int i = 1; i < 283; i++)
- {
- ECFieldElement w2 = w.Square();
- z = z.Square().Add(w2.Multiply(t));
- w = w2.Add(beta);
- }
- if (!w.IsZero)
- return null;
- gamma = z.Square().Add(z);
- }
- while (gamma.IsZero);
-
- return z;
- }
-
public virtual int M
{
get { return 283; }
|
